Macro - Sony 100 vs Sigma 105 vs Tamron 90

[deathvalleydave]

Hi David,

Regardless of price, for a mid-telephoto macro lens which would you recommend between these 3 overall and why?

I would be mounting to the A900.

Thanks,
Dave

[David Kilpatrick]

Between these three, I do not think there is any optical preference. I guess I would have to say the Sony if you can afford it as it has the best compliance with the system - the safest choice for future compatibility.

David

[KevinBarrett]

A quick comparison on Dyxum.com reveals the Sony to have the longest working distance of this set, 350mm vs the Sigma's 310mm. The Tamron will have you sneaking as close as 290mm to skittish macro subjects.

[deathvalleydave]

Technically speaking then, with 3 different focal lengths (90, 100, 105), and 3 different "closest focusing distances", which lens will give you the greatest "macro" or closest to subject image?

[David Kilpatrick]

All three do 1:1 macro, life size. It's just the working distance which is different.

David

[KevinBarrett]

What troubles most macro photography (assuming you're only shooting for 1:1 macro, and not beyond) is working distance. Obviously, the closer you are to a subject, the more uncomfortable it may be of your proximity. Also, lighting a subject becomes more difficult the closer you are to it; get close enough, and your camera will be casting a shadow on your subject. Therefore, macro lenses with longer working distances are generally coveted over shorter ones for work in the outdoors.

The minimum focus distance measures the distance from the sensor to the subject at 1:1 magnification. When you subtract from that figure the length of the lens and the depth of the mount (which is a constant in this case), you end up with an overall effective working distance from lens to subject. The Tamron 90, Sigma 105, and Sony 100 macro lenses vary in a range of only 3mm in overall lens length, but their minimum focusing distances vary by much more significant margins.

[deathvalleydave]

Thanks for the replies...

So if I understand correctly, regardless of the published minimum focus distances for these 3 macros, when you focus as close to the subject as limited by each of these 3 lenses, they will all be 1:1, and if shooting the same subject, it will be exactly the same size shot with all 3 lenses. In other words, I'm essentially trying to learn if one lens gives your "more" macro in which you can make the subject larger or get closer to it... so, if I'm understanding correctly, the answer is No, because they're all 1:1's and are just built a little differently and they all give you the same macro.

[KevinBarrett]

You are about 99% correct. They might take the same image of a perfectly flat thing which is parallel to the plane of focus, say, a postage stamp, but if you're shooting 3D real life things, you'll get marginally different angles of view and depths of field due to the different focal lengths. But then we're splitting hairs, and I can count on one hand the number of photographers I know that could appreciate the difference in that regard.

If you want to get greater than 1:1 magnification with one of these macro lenses, you can use extension tubes which fit between the lens and the camera body. These will allow closer focus, but, while fitted, the lens will not be able to focus to infinity. Some will provide coupling for the AF screw drive, some will provide contacts to allow the lens to communicate with the body, and still others will provide both, or neither. I believe any given extension tube will provide the same functionality to each of the lenses in question.

[pakodominguez]

You are about 99% correct. They might take the same image of a perfectly flat thing which is parallel to the plane of focus, say, a postage stamp, but if you're shooting 3D real life things, you'll get marginally different angles of view and depths of field due to the different focal lengths.

I understand that, at 1:1, DOP is the same regardless the focal distance, Am I wrong?